Casing for thermostatic instruments.



G.PORTER. CASING FOR THERMOSTATIG INSTRUMENTS APPLICATION FILED AUG. 20,1906.

1,021,888. I PatentdApr.2, 19

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UNITED STATES PATENT OFFICE. I

GEORGE PORTER, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO PARKER MANUFAC-TURING COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF WEST VIR-GINIA.

Specificationof Letters lfatent.

CASING FOR THERMOSTATIC INSTRUMENTS.

Application filed'August 20, 1906. Serial No. 331,259.

To all whom it may concern: Be it known that I, GEORGE PORTER, a citizenof the United States, residing in Boston,

in the county of Sufiolk and State of Massachusetts, have invented anImprovement in Casings for Thermostatic Instruments, of which thefollowing description, in connec tion with the accompanying drawings, isa specification, like letters on the drawings representing like parts.

This invention relates to a thermostatic instrument of that class inwhich a pointer is moved overa dial provided with graduations indicativeof degrees of temperature and located within an inclosing casingcontionby providing the dial with self-locking means against rotary movement aswill be described.

Figure 1 is a plan view of an instrument embodying this invention. Fig.-2, a plan view of the instrument with the glass and its retaining ringrem0ved.- Fig. 3, a section on the line 33, Fig. 2. Fig. 4, a plan ofthe dial removed, and Fig. 5, a modification to be referred to.

Referring to the drawings, a represents an inclosing casing for thecooperating parts of the thermostatic instrument, which comprise thepointer 72, graduated dial a, and the thermostat and mechanismconnecting the same with the pointer, which thermostat and mechanism arenot herein shown as they form no part of the present invention, and maybe of the construction now usually employed in instruments of thisclass. The dial 0 in accordance with this invention is provided withmeans for looking it against rotary movement and for this purpose, saiddial is provided with one or more outwardly extended lugs or projections03, which are integral with the dial and which cooperate with slots oropenings 6 in the body portion of the casing ar In the present instancethe dial 0 is provided with two substantially diametrically oppositelugs 03, which enter correspondingly located slots 6 in the body portionand which lugs rest upon inwardly extended lugs or projections f formedby bending down within the body portion a the portions of the latterwhich are out or slitted to form the slots 6, as represented in Fig. 3.

If desired, the portions or lugs f which form the slots e may beentirely removed as represented in Fig. 5, in which case the lugs d onthe dial may rest on the bottom wall of Patented Apr. 2, 1912.

the slots e in the body portion of the casing.

By means of the lugs on the dial extended into the slots or openings inthe case, the said dial is locked against rotary movement and withoutthe necessity of employing the screws or rivets now commonly employed,and as a result the cost of construction, and the time and laboremployed for assembling the parts are materially reduced, therebyenabling the instrument to be manufactured and sold at a minimum price.

Claims:

1. In an instrument of the class referred to, in combination, a dial, aninclosing casing for said dial comprising a bottom having outwardlyextended lugs provided with openings and a circular body portion open atits top and provided with a slot or opening at the upper edge thereof,and a lug or projection on said dial extended outwardly from said dialin the plane of the latter. and into said opening to rest upon thebottom wall of said slot and support the dial above the bottom of thecasing and lock it against rotary movement, substantially as described.

2. In an instrument of the class referred to, in combination, a pointer,a dial with which said pointer cooperates, an inclosing casing having aplurality of-slots or openings in its body portion at the edge thereofand lugs or projections extended Within the casing in line With saidopenings, and lugs or projections on said dial extended outwardly fromsaid dial and into said openings and resting on the lugs of the saidbody portion, substantially as described.

In testimony whereof, I have signed my name to this specification in thepresence of two subscribmg wltnesses.

GEORGE PORTER. Witnesses M. E. HUNT, M. M. BLODGETT.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

